Route-guidance control device, route-guidance control method, and navigation system

ABSTRACT

A configuration includes: a search unit to access to a map database storing map information to search for a destination corresponding to an input linguistic expression, using a plurality of search criteria provided with orders of priority; and a destination setting unit to set a first destination corresponding to the input linguistic expression, in accordance with the orders of priority.

TECHNICAL FIELD

The invention relates to a route-guidance control device, route guidancemethod, and navigation system which set a destination area by a vagueinstruction in route guidance by an automotive navigation system or thelike, and then provide route guidance to a final destination asnecessary.

BACKGROUND ART

A conventional automotive navigation system sets one specific spot as adestination and computes a route. For methods for setting a specificspot as a destination, there are searches such as a search for the namesof facilities, a search for addresses, a search for telephone numbers,and a search for categories of facilities.

However, setting one specific spot as a destination involves a lot ofoperational steps and also requires operating time. By this, operationstake time, thus making it difficult to allow a vehicle to start to runimmediately.

To address this issue, for example, there is the configuration asdisclosed in Patent Literature 1 which is capable of setting adestination to a predetermined area (region), not to one specific spot,to search for a route, and causing the map of a destination'sneighborhood to be displayed on a screen of an automotive navigationsystem. In Patent Literature 1, the address of a spot being at thecenter of a display region and a display scale are recognized, anadministrative region serving as the destination's neighborhood isrecognized based on contrast data, and the route to be followed that hasthe shortest distance from the current location to an intersection pointbetween a road and an administrative boundary is searched for. When avehicle has reached near the administrative boundary, guidance isprovided to prompt a user to input for a setting as to whether to searchfor rerouting. A destination neighborhood at the user's destination canbe set in the range depending on the degree of user's vagueness aboutthe destination, and, thus, the route to the vague destination can beeasily searched for.

In addition, for example, there is a configuration as disclosed inPatent Literature 2 which is capable of building in advance the areadata that contains the location coordinates of spots such as primaryintersections and the fronts of train stations in each area such asHakone or Gotemba, and, for the setting of the area name “Hakone” for adestination upon a route search, extracting the location coordinates ofspots contained in the target area from the area data to set theextracted location coordinates as the location coordinates ofdestinations, and, thereafter, searching for routes from the vehicle'scurrent location indicating a starting spot to a plurality of otherspots. The configuration carries out an operation of searching for aroute using as a destination the closest spot to the starting spot, andallows a display monitor to display the operation result for routeguidance.

CITATION LIST Patent Literatures

Patent Literature 1: Japanese Patent Application Publication No.2007-240438.

Patent Literature 2: Japanese Patent Application Publication No.2004-219243.

SUMMARY OF INVENTION Technical Problem

However, the conventional art as disclosed in Patent Literature 1requires displaying the map of the destination's neighborhood on ascreen. Namely, there is the problem that a route search cannot beperformed unless the place on a map where the user wants to go is known.

In addition, in the conventional art as disclosed in Patent Literature2, there is a need to build the area data in advance, thus causing theproblem that a route search cannot be performed for the locations thatare not contained in the area data.

The invention is made to solve the above problems, and an object of theinvention is to provide a route-guidance control device, route-guidancecontrol method, and navigation system which are capable of performing aroute search by a vague instruction that includes nearly human feelingsas if a user tells a taxi driver as to where the user wants to go, evenwithout knowing the location on a map where the user wants to go to, oreven without the building of area data in advance, and allowing avehicle to start to run immediately toward the area where the user wantsto go to.

Solution to Problem

A route-guidance control device according to the invention includes: asearch unit to access to a map database storing map information tosearch for a destination corresponding to an input linguisticexpression, using a plurality of search criteria provided with orders ofpriority; a destination setting unit to set a first destinationcorresponding to the input linguistic expression, in accordance with theorders of priority; and a destination's neighboring area setting unit toset a range of a first destination's neighboring area, in accordancewith a distance between a current location and the first destination.

A route-guidance control method according to the invention includes thesteps of: accessing to a map database storing map information to searchfor a destination corresponding to an input linguistic expression, usinga plurality of search criteria provided with orders of priority, in asearch unit; setting a first destination corresponding to the inputlinguistic expression in accordance with the orders of priority, in adestination setting unit; and setting a range of a first destination'sneighboring area, in accordance with a distance between a currentlocation and the first destination, in a destination's neighboring areasetting unit.

A navigation system according to the invention is a navigation system inwhich a route-guidance control device allows a display device to displaya route to a destination by using map information stored in a mapdatabase. The route-guidance control device includes: a search unit toaccess to a map database storing map information to search for adestination corresponding to an input linguistic expression, using aplurality of search criteria provided with orders of priority; adestination setting unit to set a first destination corresponding to theinput linguistic expression, in accordance with the orders of priority;and a destination's neighboring area setting unit to set a range of afirst destination's neighboring area, in accordance with a distancebetween a current location and the first destination.

Advantageous Effects of Invention

According to the invention, it is possible to perform the route searchby a vague instruction and, thus, a vehicle can start to run immediatelytoward the area where a user wants to go to. Further, burdens on thenumber of operations and operating times for a route search can bereduced. Furthermore, without the building of area data in advance, theroute search can be performed by an area name.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a configuration diagram of a route-guidance control deviceaccording to a first embodiment of the invention.

FIG. 2 is a flowchart for describing the operation of the route-guidancecontrol device according to the first embodiment of the invention.

FIG. 3 is a diagram showing examples of a plurality of search criteriato be used when a destination setting unit sets a destination.

FIGS. 4A and 4B are diagrams illustrating examples of presentingcandidates for destinations to a user.

FIG. 5 is a configuration diagram of a route-guidance control deviceaccording to a second embodiment of the invention.

FIG. 6A is a flowchart for describing the operation of theroute-guidance control device according to the second embodiment of theinvention.

FIG. 6B is a flowchart for describing the operation of theroute-guidance control device according to the second embodiment of theinvention.

FIG. 7 is a diagram showing examples of conditions for setting a rangeof a destination's neighboring area in a destination's neighboring areasetting unit.

FIG. 8 is a diagram showing other examples of conditions for setting arange of a destination's neighboring area in the destination'sneighboring area setting unit.

FIGS. 9A to 9C illustrate examples of specific images showing distancesbetween a destination and current locations, and showing destination'sneighboring areas on a map.

FIGS. 10A and 10B are diagrams illustrating examples for adjusting arange of a destination's neighboring area by an input linguisticexpression.

FIG. 11 is a diagram showing an example of a screen display of adestination's neighboring area.

FIG. 12 is a diagram for describing an example of a state in which acurrent location has approached a circumference of a destination'sneighboring area.

FIGS. 13A and 13B are diagrams illustrating an example of the operationof narrowing a destination's neighboring area.

FIGS. 14A and 14B are diagrams illustrating examples for presentingcandidates for destination areas to a user.

FIG. 15 is a configuration diagram of a route-guidance control deviceaccording to a third embodiment of the invention.

FIG. 16 is a flowchart for describing the operation of theroute-guidance control device according to the third embodiment of theinvention.

FIG. 17 is a configuration diagram of a route-guidance control deviceaccording to a fourth embodiment of the invention.

FIG. 18 is a flowchart for describing the operation of theroute-guidance control device according to the fourth embodiment of theinvention.

FIGS. 19A and 19B are diagrams illustrating examples for setting adestination using two keywords.

FIG. 20 is a configuration diagram of a route-guidance control deviceaccording to a fifth embodiment of the invention.

FIG. 21 is a flowchart showing the operation of the route-guidancecontrol device according to the fifth embodiment of the invention.

FIGS. 22A and 22B are diagrams illustrating examples for setting thecoordinates of a location of characters on a map as a destination.

FIG. 23 is a flowchart for describing the operation of a route-guidancecontrol device according to a sixth embodiment of the invention.

FIG. 24 is a diagram showing an example for setting a destination usinga distribution of facilities.

FIG. 25 is a flowchart for describing the operation of a route-guidancecontrol device according to a seventh embodiment of the invention.

FIG. 26 is a diagram showing an overview of a navigation system of aneighth embodiment of the invention.

DESCRIPTION OF EMBODIMENTS

Embodiments of the invention will be described in detail below withreference to the drawings.

First Embodiment

FIG. 1 is a configuration diagram of a route-guidance control deviceaccording to a first embodiment of the invention.

The route-guidance control device includes a destination setting unit 1,a map database (hereinafter, referred to as a map DB) 2, a route searchunit 3, and a route guidance unit 4.

The destination setting unit 1 includes a search unit that searches fora destination for each of a plurality of search criteria, and can set adestination based on the search results obtained using a plurality ofpredetermined search criteria and based on data about a linguisticexpression input by voice or text from an input device (not shown).Specifically, when the map DB 2 does not include a linguistic expressionthat matches an input linguistic expression, the destination settingunit 1 sets, as will be described below, for example, a temporarydestination using map information that includes the input linguisticexpression. Orders of priority are set for the plurality of searchcriteria, and the destination setting unit 1 sets a destination suchthat a high-priority search criterion has precedence.

The map DB 2 contains map-related data (map information) such as thenames of facilities and/or the location information of facilities.

The route search unit 3 performs a route search to search for a routefrom a current location to the destination.

The route guidance unit 4 provides route guidance based on the result ofthe route search performed by the route search unit 3.

The operation of the route-guidance control device according to thefirst embodiment of the invention will be described.

FIG. 2 is a flowchart for describing the operation of the route-guidancecontrol device according to the first embodiment of the invention.

The destination setting unit 1 receives data about a linguisticexpression input from the input device, i.e., data about where a userwants to go (step ST100). In this regard, the user's inputting of theplace where the user wants to go can be completed by a voicerecognition, the inputting of a text, or the like, and the inputting canbe made by any means. At that time, for example, the input device maygenerate an audio output such as “Where do you go for the moment?” or“Which area do you go?” to ask the user a question. This can prompt orinduce the user to input a vague linguistic expression or the name of anarea. Further, “Where do you go for the moment?”, “Which area do yougo?” or other message can be displayed in a screen. A combination of anaudio output and a screen display can be performed.

The destination setting unit 1 sets a destination based on the searchresults obtained by using a plurality of preset search criteria inaccordance with the data received at step ST100, i.e., the data aboutthe linguistic expression input by the user (step ST110). At that time,the data contained in the map DB 2, such as facility information and/orthe location information of facilities, is used.

FIG. 3 is a diagram showing examples of a plurality of search criteriato be used when the destination setting unit 1 sets a destination.

As shown in FIG. 3, orders of priority are set for the plurality ofsearch criteria, and in FIG. 3 the search criteria are assigned theorders of priority: 1, 2, . . . , in descending order of priority.

The destination setting unit 1 sets a destination by performing a searchfor each of the plurality of search criteria such as those shown in FIG.3. Location information indicating the determined destination isobtained from the map DB 2.

For example, when a linguistic expression input by the user is“Shin-Yokohama”, since there is a “station” having the same name as theinput linguistic expression, the destination setting unit 1 obtainslocation information indicating “Shin-Yokohama Station” from the map DBand sets the location information as a destination. When a linguisticexpression input by the user is “Hakone”, although there is no “station”having the same name as the input linguistic expression, i.e., “HakoneStation”, since there is the “name of prefecture or municipality” havingthe same name as the input linguistic expression, the destinationsetting unit 1 obtains location information indicating “Hakone TownHall” from the map DB and sets the location information as adestination. In the case where a linguistic expression input by the useris “Yokohama Tower”, although there is no “station” or “name ofprefecture or municipality” having the same name as the input linguisticexpression such as “Yokohama Tower Station” or “Yokohama TowerPrefecture”, there is a “name of facility” having the same name as theinput linguistic expression. In this case, the destination setting unit1 obtains location information indicating “Yokohama Tower” from the mapDB 2 and sets the location information as it is as a destination spot.In the case where a linguistic expression input by the user is“Dogenzaka”, although there is no “station”, “name of prefecture ormunicipality”, or “name of facility” which has the same name as theinput linguistic expression such as “Dogenzaka Station”, “DogenzakaPrefecture” or “Dogenzaka”, there is an “intersection” having the samename as the input linguistic expression. In this case, the destinationsetting unit 1 obtains location information indicating “DogenzakaIntersection” from the map DB and sets the location information as adestination.

As such, it is determined which location information should be treatedas a destination in accordance with an input linguistic expression.

In this regard, since the orders of priority are set for the pluralityof search criteria, the destination setting unit 1 may perform a searchin descending order of priority and terminate the search when adestination is found. Alternatively, the destination setting unit 1 mayperform a search for all of the plurality of search criteria, and, whena plurality of destinations are set, the destination setting unit 1 mayset one of the candidates that matches a high-priority search criterion,as a destination. For example, when, as the result of a destinationsearch for each of the plurality of search criteria of FIG. 3, an inputlinguistic expression is included in both a station name and a name ofmunicipality, the destination setting unit 1 sets the station name as adestination. Specifically, for example, when “Yokohama” is input,“Yokohama Station” rather than “Yokohama City Hall” is set as adestination.

The plurality of search criteria are not limited to those shown in FIG.3 and can be set as appropriate.

The route search unit 3 performs a route search for a route from thecurrent location to the destination (step ST120). The route search maybe performed using existing techniques.

The route guidance unit 4 provides route guidance in accordance with theroute set by the route search unit 3 at step ST120 (step ST130). Theroute guidance may be provided using existing techniques.

When, upon the setting of destinations by the destination setting unit 1at step ST110, a plurality of destinations with the same name can beset, it is also possible to present candidates to the user so as toprevent a user's unintended destination from being automatically set.Specifically, for example, when the destination “Ryokuchi Koen” thatexists at Kamakura City in Kanagawa Prefecture, at Yokohama City inKanagawa Prefecture, and at Shibuya Ward in Tokyo can be set, as shownin FIG. 4A, the candidates for “Ryokuchi Koen” that are possiblydestinations can be displayed in a list on a touch panel screen of adisplay device (not shown). In addition, as shown in FIG. 4B, a map maybe displayed on the touch panel screen of the display device (notshown). By doing so, the user can check the candidates for a destinationon the screen and determine a destination, and accordingly, a user'sunintended destination can be prevented from being automatically set.

In addition to the presentation methods shown in FIGS. 4A and 4B, forexample, candidates for a destination may be displayed on a screen andthe user may decide a destination using a hardware selection buttoninstalled on a steering wheel or the like. Alternatively, for example,the sentence for checking ““Ryokuchi Koen” in Kamakura? In Yokohama? InShibuya?” or ““Ryokuchi Koen” in Kamakura?” may be output by voiceguidance, and the user may answer a message such as “Kamakura” or“Yokohama” by voice. As such, a method for presenting a plurality ofcandidates for a destination to the user can be selected as appropriate.

As described above, according to the first embodiment, even if an inputlinguistic expression is vague, a destination can be set. Further, evenwithout preparing in advance, for example, destination data associatedwith areas, a destination can be set. In addition, burdens on the numberof operations and operating time for a route search can be furtherreduced.

Second Embodiment

In the first embodiment, the embodiment has been described in which evenif an input linguistic expression is vague, a destination can be set.Alternatively, since a user's vague instruction for a destinationincludes a nuance such as “XX area”, “direction of XX”, or “around XX”,there is the possibility that a destination may differ from the spotwhere a user wants to go. Hence, it may be appropriate that the locationwhere the user wants to go be taken as an area having a two-dimensionalarea and the area be narrowed step by step to thereby become an accuratedestination.

In the second embodiment, an embodiment will be described in which anarea of a user's intended location where the user wants to go(destination's neighboring area) is set and a range (extent) of thedestination's neighboring area is variably made depending on a distancebetween a current location and a destination, and, for example, when theuser has approached near the boundary of the destination's neighboringarea, the destination is reset and the area where the user should travelto is further narrowed.

FIG. 5 is a configuration diagram of a route-guidance control deviceaccording to the second embodiment of the invention.

Note that overlapping descriptions of the same configurations as thosedescribed with respect to FIG. 1 in the first embodiment will beomitted.

The difference between the second embodiment and the first embodimentis, as shown in FIG. 5, that the device further includes a destination'sneighboring area setting unit 5, a current-location acquiring unit 6, aninquiry timing decider 7, an inquiry sentence generator 8, and an inputunit 9.

The destination's neighboring area setting unit 5 calculates, based on adestination received from a destination setting unit 1 and locationinformation indicating a current location received from thecurrent-location acquiring unit 6, the distance between the currentlocation and the destination, and sets a destination's neighboring areabased on the calculated distance between the current location and thedestination.

The current-location acquiring unit 6 acquires the location informationindicating the current location by GPS or the like.

The inquiry sentence generator 8 receives data about a linguisticexpression input last time from the destination setting unit 1 andgenerates a sentence of inquiry to ask the user.

The inquiry timing decider 7 receives the current location from thecurrent-location acquiring unit 6 and receives a range of thedestination's neighboring area from the destination's neighboring areasetting unit 5. When inquiry timing comes, the inquiry timing decider 7voice-outputs or display-outputs the inquiry sentence generated by theinquiry sentence generator 8.

The input unit 9 is a hardware button such as a button on a touch panelscreen that receives user's instructions. The input unit 9 may beincluded in the route-guidance control device or may be providedexternal to the route-guidance control device.

FIGS. 6A and 6B are flowcharts for describing the operation of theroute-guidance control device according to the second embodiment of theinvention. With reference to FIGS. 6A and 6B, the operation will bedescribed.

Since steps ST100, ST110, ST120, and ST130 in FIG. 6A have the sameoperation as steps ST100, ST110, ST120, and ST130 shown in FIG. 2 in thefirst embodiment, respectively, the overlapping descriptions will beomitted. It is assumed that a destination is set using the plurality ofsearch criteria of FIG. 3.

The destination's neighboring area setting unit 5 receives locationinformation indicating a destination (hereinafter, referred to as afirst destination) that is set by the destination setting unit 1 at stepST110 as well as location information indicating a current locationobtained by the current-location acquiring unit 6, and computes adistance between the current location and the first destination, basedon the two pieces of received location information. In this regard, thedistance as used herein includes a straight-line distance and journeyinformation.

Furthermore, the destination's neighboring area setting unit 5 sets arange (extent) of a destination's neighboring area (hereinafter,referred to as a first destination's neighboring area), based on thecomputed distance between the current location and the first destination(step ST220).

A specific method for setting a range of a destination's neighboringarea will be described.

FIG. 7 is a diagram showing examples of conditions for setting a rangeof a destination's neighboring area in the destination's neighboringarea setting unit 5.

Under conditions such as those shown in FIG. 7, the destination'sneighboring area setting unit 5 sets a range of a destination'sneighboring area in accordance with a distance between a currentlocation and a destination. For example, when the distance between thecurrent location and the destination is 1 km, the destination'sneighboring area setting unit 5 sets a range of a destination'sneighboring area to a radius of 100 m. In this regard, the conditionsfor setting a range of a destination's neighboring area can be set asappropriate and are stored in advance in the destination's neighboringarea setting unit 5.

FIG. 8 is a diagram showing other examples of conditions for setting arange of a destination's neighboring area in the destination'sneighboring area setting unit 5.

As shown in FIG. 8, the destination's neighboring area setting unit 5may store the graph that defines relationship between a distance betweena current location and a destination and a radius of a destination'sneighboring area, or may store data that defines relationship as amathematical expression. As such, how to define the conditions fordetermining a range of a destination's neighboring area is notparticularly limited.

FIGS. 9A to 9C illustrate examples of specific images showing thedistances between destinations and current locations, and showingdestination's neighboring areas on a map.

For example, when an input linguistic expression is “Yokohama”, thedestination setting unit 1 uses location information indicating“Yokohama Station” as a destination. When, as shown in FIG. 9A, acurrent location is Shizuoka City, Shizuoka Prefecture, since thedistance between the current location and Yokohama Station is about 100km, the destination's neighboring area setting unit 5 sets the radius ofa destination's neighboring area having Yokohama Station at the centerto 10 km. In addition, when, as shown in FIG. 9B, a current location isChigasaki City in Kanagawa Prefecture, since the distance between thecurrent location and Yokohama Station is about 30 km, the destination'sneighboring area setting unit 5 sets the radius of a destination'sneighboring area having Yokohama Station at the center to 3 km. Inaddition, when, as shown in FIG. 9C, a current location is Totsuka Ward,Kanagawa Prefecture, since the distance between the current location andYokohama Station is about 10 km, the destination's neighboring areasetting unit 5 sets the radius of a destination's neighboring areahaving Yokohama Station at the center to 1 km.

As such, when the destination is far from the current location, thedestination's neighboring area is wide, and when the destination isclose to the current location, the destination's neighboring area isnarrow.

Note that here the destination's neighboring area is circular, but isnot limited to a circular shape and may be oval or square, or may be aprefecture or a city. The shape of the destination's neighboring areamay be arbitrary.

In addition, the destination setting unit 1 may store data as to whichsearch criterion is used to set a destination when the destination isset, i.e., data indicating the degree of match between an inputlinguistic expression and the set destination. The destination'sneighboring area setting unit 5 may set the size of a destination'sneighboring area, according to which the search criterion is used to setthe destination to be stored in the destination setting unit 1. Forexample, when an input linguistic expression is the same as the name ofa facility or the name of an intersection, a destination's neighboringarea may be set to be narrow. When the name of any facility,intersection or other location that is the same as the input linguisticexpression does not exist and a destination is set using locationinformation indicating a station or a government office, thedestination's neighboring area may be set to be wide.

This will be described referring to FIGS. 10A and 10B.

FIG. 10A is a diagram illustrating an example of a range of adestination's neighboring area for a case of the input “YokohamaStation”.

FIG. 10B is a diagram illustrating an example of a range of adestination's neighboring area for a case of the input “Yokohama”.

For example, in both of the case of the input “Yokohama Station” asshown in FIG. 10A and the case of the input “Yokohama” as shown in FIG.10B, the destination setting unit 1 sets the same “Yokohama Station” asa destination. On the other hand, in the case of the input “YokohamaStation”, the name of facility “Yokohama Station” exists in the map DB 2and thus there is matching location information, whereas in the case ofthe input “Yokohama”, there is no matching location information in themap DB 2 and thus a destination is set based on location informationindicating a station name. That is, it can be said that the case of theinput “Yokohama Station” is more likely that the destination is alocation where the user wants to go. Hence, the destination'sneighboring area setting unit 5 stores the conditions such that a narrowdestination's neighboring area is set for the case of the input“Yokohama Station”, as shown in FIG. 10A, and a wide destination'sneighboring area is set for the case of the input “Yokohama”, as shownin FIG. 10B, and sets a destination's neighboring area based on theconditions. In this way, the range of an area can be approximated to theone expected by the user.

The description returns to the flow of FIG. 6A.

After a route search unit 3 searches for a route at step ST120, a routeguidance unit 4 provides route guidance at step ST130. At this time, thedestination's neighboring area setting unit 5 may transmit a signal fordisplaying the first destination's neighboring area set at step ST220,to a display device (not shown) for a screen display (see FIG. 11). Notethat display may be performed such that, as shown by a dotted line and asolid line in FIG. 11, the user can see a search route in adestination's neighboring area and a search route from a currentlocation to where the user has approached the destination's neighboringarea. Note also that the display device may be included in theroute-guidance control device or may be provided external to theroute-guidance control device.

The inquiry sentence generator 8 generates a sentence of inquiry (stepST300). Specifically, the destination setting unit 1 has stored alinguistic expression input last time (data received at step ST100), andthe inquiry sentence generator 8 receives the data about the linguisticexpression input last time from the destination setting unit 1, andgenerates an inquiry sentence based on the received data about thelinguistic expression. For example, when the destination setting unit 1receives “Yokohama” at step ST100, the inquiry sentence generator 8generates an inquiry sentence such as “Where in Yokohama do you go?” or“Where in Yokohama?”. Alternatively, for example, when the destinationsetting unit 1 receives “Yokohama Station” at step ST100, the inquirysentence generator 8 generates an inquiry sentence such as “Whereaboutsin Yokohama Station?”. Note that the inquiry sentences are not limitedthereto and may be arbitrary as long as the content of an inquirysentence allows to obtain an answer by which the area can be furthernarrowed.

The inquiry timing decider 7 decides whether the location of the user'svehicle becomes a certain location close to the boundary of the firstdestination's neighboring area that was set last time (set at stepST220) (step ST310). In this regard, the “certain location close to theboundary of the destination's neighboring area” may be a spot where theuser's vehicle location has entered the destination's neighboring area.As such, “near the boundary of the destination's neighboring area” maybe any location that is determined in advance based on the currentlocation and the location of the destination's neighboring area. It isassumed that, as shown in FIG. 12, the spot where the current locationhas approached a circumference of the first destination's neighboringarea is where the user's vehicle location has reached near the boundaryof the destination's neighboring area.

If the user's vehicle location has come near the boundary of the firstdestination's neighboring area at step ST310 (if “YES” at step ST310),processing proceeds to step ST330. On the other hand, if the user'svehicle location has not reached near the boundary of the firstdestination's neighboring area at step ST310 (“NO” at step ST310), theinquiry timing decider 7 decides whether an input button has beenpressed, i.e., whether there has been an input from the input unit 9(step ST320). The input unit 9 is, for example, a hardware button placedon a steering wheel or a center console, or a button displayed on aliquid crystal touch panel. The user can press such a button when theuser wants to actively narrow the destination's neighboring area,thereby forcing an inquiry timing signal to be transmitted to theinquiry timing decider 7.

That is, when the user approaches near the boundary of the destination'sneighboring area, the user is automatically asked, and when the userpresses the button before approaching near the boundary of thedestination's neighboring area, the user can be asked at that timing.For example, if the button or the like is pressed when the user waits ata stop-light, the destination's neighboring area can be narrowed. Inaddition, by pressing the button whenever the user wants, thedestination's neighboring area can be narrowed immediately.

If the input button has not been pressed at step ST320 (if “NO” at stepST320), processing returns to step ST310. On the other hand, if theinput button has been pressed at step ST320 (if “YES” at step ST320),processing proceeds to step ST330.

The inquiry timing decider 7 allows an output device (not shown) tooutput the inquiry sentence generated by the inquiry sentence generator8 at step ST300 (step ST330). Specifically, for example, an inquirysentence such as “Where in Yokohama do you go?” or “Where in Yokohama?”is output by voice, or an inquiry sentence is displayed on a screen, orboth a voice output and screen display are performed. In response tothis, the user answers the inquiry question by inputting a linguisticexpression that further narrows the destination area. Here, it isassumed that, for example, “Chinatown” is input.

The destination setting unit 1 receives data about the additionallinguistic expression (“Chinatown”) (step ST340). Furthermore, thedestination setting unit 1 sets a destination (hereinafter, referred toas a second destination) within the last destination's neighboring area,i.e., within the range of the first destination's neighboring area,based on the additional linguistic expression received at step ST340(step ST350). For example, as shown in FIG. 13A, “Chinatown” is searchedfor within the range of the first destination's neighboring area, bywhich the second destination is set. Note that a specific setting methodfor the second destination is the same as that for the firstdestination. By doing so, several candidates for a destination areexcluded. For example, when inputs are performed in order of“Shibuya”→“Japan A Hotel”, it is only necessary to search for a Japan AHotel in the Shibuya area. That is, Japan A Hotels in Yokohama,Shinagawa, Shinjuku, Ikebukuro and other location are excluded fromsearch results.

Thereafter, route guidance is provided using the second destination as adestination (FIG. 13B).

The destination's neighboring area setting unit 5 sets a range of adestination's neighboring area (hereinafter, referred to as a seconddestination's neighboring area), based on the distance between thecurrent location and the second destination (step ST360). A specificdetermination method for the second destination's neighboring area isthe same as the determination method for the first destination'sneighboring area.

The route search unit 3 searches for a route from the current locationto the second destination (step ST370). Thereafter, the route guidanceunit 4 provides route guidance to the second destination (step ST380),and processing ends. Specific operations at steps ST370 and ST380 arethe same as those at steps ST120 and ST130.

When the inquiry timing decider 7 decides at step ST310 that the user'svehicle location has come near the boundary of the destination'sneighboring area or when the inquiry timing decider 7 decides at stepST320 that there has been an input from the input unit 9, the firstdestination's neighboring area may be displayed on the display device.In addition, the first and second destination's neighboring areas may beor may not be displayed on a screen at all times. The first and seconddestinations may be or may not be displayed on a screen at all times,too.

Note that in the second embodiment, too, as in the first embodiment,when, upon the setting of the first destination in the destinationsetting unit 1 at step ST110, a plurality of destinations with the samename can be set, it is also possible to present candidates to the userso as to prevent a user's unintended destination from beingautomatically set. Specifically, for example, when the area of the firstdestination “Ryokuchi Koen” that exists in Kamakura City, KanagawaPrefecture, in Yokohama City, Kanagawa Prefecture, and in Shibuya Ward,Tokyo can be set, as shown in FIG. 14A, a plurality of candidates for“Ryokuchi Koen Area” that can be a destination can be displayed in alist on a touch panel screen of a display device (not shown). Inaddition, as shown in FIG. 14B, a map may be displayed on the touchpanel screen of the display device (not shown). By doing so, the usercan check the candidates for a destination area on the screen and set adestination area, and accordingly, a user's unintended destination areacan be prevented from being automatically set.

In addition to the presentation methods shown in FIGS. 14A and 14B, forexample, candidates for a destination area may be displayed on a screenand the user may determine a destination area using a hardware selectionbutton installed on a steering wheel or the like. Alternatively, forexample, the sentence for checking “Is “Ryokuchi Koen” area in Kamakura?an area in Yokohama? or other area in Shibuya?” or “Is “Ryokuchi Koen”area in Kamakura?” can be output by voice guidance, and the user mayanswer a message such as “area in Kamakura.” or “area in Yokohama.” byvoice. As such, a method for presenting a plurality of candidates for adestination to the user can be selected as appropriate.

As described above, according to the second embodiment, since adestination's neighboring area that the user wants to go to isdetermined, when the destination's neighboring area is displayed, theuser can easily see, for example, which area the user is heading to,what extent of area the user is heading to as a target, or whether alocation that the user wants to go to is included in the destination'sneighboring area. In addition, by changing a range of the destination'sneighboring area depending on how a destination is set based on an inputlinguistic expression, when the destination's neighboring area isdisplayed on a screen, the displayed area can be further approximated tothe one imaged by the user.

Furthermore, when the user's vehicle location has approached near theboundary of the destination's neighboring area, an area or a locationthat the user wants to go to is narrowed within the range of thedestination's neighboring area which is set initially, and thus, searchresults are narrowed, enabling to produce a search route to a morespecific destination's direction. In addition, it is also possible toproduce a search route to a more specific destination's direction at anytiming the user wants, and thus, the user can perform an operation ofnarrowing the destination's neighboring area toward a specificdestination's direction when the vehicle stops at a red light or attiming at which the user stops the vehicle for taking a break, forexample.

Third Embodiment

In the second embodiment, the embodiment has been described in which thedestination's neighboring area is narrowed. Alternatively, even if adestination's neighboring area is narrowed a plurality of times, since adestination's neighboring area having a two-dimensional area can bealways set, a pinpoint destination where a user wants to go finally(hereinafter referred to as a final destination) may need to be set.

In the third embodiment, an embodiment will be described in which aroute to a final destination is searched for and guided.

FIG. 15 is a configuration diagram of a route-guidance control deviceaccording to the third embodiment of the invention.

Note that overlapping descriptions of the same configurations as thosedescribed in FIGS. 1 and 5 in the first and second embodiments will beomitted.

The difference between the third embodiment and the second embodimentis, as shown in FIG. 15, that the device further includes a keyworddiscriminator 10 and a destination determination unit 11.

The keyword discriminator 10 receives data about a linguistic expressioninput by a user and decides whether a linguistic expression input lasttime is the same as the linguistic expression input this time. Note thatfor the first input, the keyword discriminator 10 transmits receiveddata about a linguistic expression as it is to a destination settingunit 1, and for the second and subsequent reception, the keyworddiscriminator 10 decides whether the linguistic expression is the sameas the last linguistic expression and transmits the result of thedecision to the destination setting unit 1.

The destination determination unit 11 decides which one of a pluralityof search criteria is used to determine a destination which is set bythe destination setting unit 1, and transmits the result of the decisionto an inquiry sentence generator 8. In this regard, the destinationsetting unit 1 has stored data as to which search criterion is used toset a destination when setting the destination, and transmits the searchcriterion to the destination determination unit 11.

FIG. 16 is a flowchart for describing the operation of theroute-guidance control device according to the third embodiment of theinvention. With reference to FIG. 16, the operation will be described.Note that it is assumed that a plurality of search criteria fordetermining a destination are those shown in FIG. 3.

It is assumed that the operation of FIG. 16 is performed after theoperations at steps ST100, ST110, and ST220 to ST130 of FIG. 6A in thesecond embodiment. It is assumed that in the process at step ST100 thekeyword discriminator 10 receives a linguistic expression input for thefirst time and transmits the linguistic expression as it is to thedestination setting unit 1.

The destination determination unit 11 decides which search criterion isused to determine a destination which is set by the destination settingunit 1, and transmits the result of the decision to the inquiry sentencegenerator 8 (step ST400).

When the inquiry sentence generator 8 receives the result of thedecision made by the destination determination unit 11 at step ST400,the inquiry sentence generator 8 generates a sentence of inquiry inaccordance with the content of the received result of the decision (stepST410).

Specifically, for example, when an input linguistic expression is“Shin-Yokohama” and the destination setting unit 1 sets a destination to“Shin-Yokohama Station” using a first-priority search criterion of FIG.3, an inquiry sentence questioning “Where in Shin-Yokohama do you go?”is generated. Alternatively, when an input linguistic expression is“Hakone” and the destination setting unit 1 sets a destination to“Hakone Town Hall” using a second-priority search criterion of FIG. 3,an inquiry sentence questioning “Where in Hakone do you go?” isgenerated. Note that data about an input linguistic expression isreceived by the destination determination unit 11 from the destinationsetting unit 1 and transmitted together with the result of the decisionto the inquiry sentence generator 8.

On the other hand, for example, when an input linguistic expression is“Yokohama Tower” and the destination setting unit 1 sets a destinationto “Yokohama Tower” using a third-priority search criterion of FIG. 3,the inquiry sentence generator 8 generates an inquiry sentencequestioning “Where in the Yokohama Tower Area do you go? Or do you go toYokohama Tower?”.

As such, the inquiry sentence generator 8 generates an inquiry sentencebased on the result of the decision made by the destinationdetermination unit 11.

Note that the above-described inquiry sentences are examples and otherexpressions may be used.

When the inquiry sentence generator 8 generates an inquiry sentence atstep ST410, an inquiry timing decider 7 decides whether a user's vehiclelocation has become near a boundary of a destination's neighboring area(first destination's neighboring area) which was set last time (stepST310). In addition, the inquiry timing decider 7 decides whether aninput button has been pressed (step ST320). Specific operations at thesesteps ST310 and ST320 are the same as those at steps ST310 and ST320 ofFIG. 6B and thus the detailed descriptions will be omitted.

If it is decided at step ST310 that the user's vehicle location hasbecome near the boundary of the destination area (first destination'sneighboring area) which was set last time (if “YES” at step ST310), orif it is decided at step ST320 that the input button has been pressed(if “YES” at step ST320), the inquiry timing decider 7 allows an outputdevice (not shown) to output the inquiry sentence generated by theinquiry sentence generator 8 at step ST410 (step ST432). Note that theinquiry sentence may be output by voice or may be output on a screen.Alternatively, both voice and screen outputs may be performed. Inresponse to this, the user answers the inquiry question by furtherinputting a linguistic expression. In this regard, it is assumed that,for example, “Japan A Hotel” or “Yokohama Station” is input.

The keyword discriminator 10 receives data about the additionallinguistic expression (step ST433).

When the keyword discriminator 10 receives the data about the additionallinguistic expression at step ST433, the keyword discriminator 10decides whether the linguistic expression input this time is the same asthe linguistic expression input last time (the linguistic expressionreceived at step ST100 of FIG. 6A) (step ST434). Specifically, thekeyword discriminator 10 has stored the received data about thelinguistic expression, and decides whether the linguistic expressioninput this time is the same as the linguistic expression input lasttime, based on the data about the linguistic expression received lasttime and the data about the additional linguistic expression.

If the linguistic expression input additionally is different from thelinguistic expression input last time at step ST434 (if “NO” at stepST434), processing proceeds to step ST435. On the other hand, if thelinguistic expression input additionally is the same as the linguisticexpression input last time at step ST434 (if “YES” at step ST434),processing proceeds to step ST438. For example, when the linguisticexpression input last time is “Yokohama Station”, if the linguisticexpression input this time is “Japan A Hotel”, processing proceeds tostep ST435. If the linguistic expression input this time is “YokohamaStation”, processing proceeds to step ST438.

At step ST438, the destination setting unit 1 sets the currently setdestination, i.e., the last destination (first destination), to be afinal destination. Specifically, if the linguistic expression input lasttime is the same as the linguistic expression input this time, then itcan be said that it is highly likely that the user wants it to be adestination, and thus, it is decided that any further inquiry questionor any further narrowing of the destination is not necessary. Forexample, when the linguistic expression input last time is “YokohamaStation” and the linguistic expression input this time is also “YokohamaStation”, “Yokohama Station” is set as a final destination. Thereafter,an output of an inquiry question is not performed and route guidance tothe final destination is provided. Note that the final destinationrefers to a pinpoint location that the user wants to arrive finally.

A route search unit 3 searches for a route from a current location tothe final destination (step ST439), and a route guidance unit 4 providesroute guidance to the final destination (step ST380). Specificoperations at these steps ST439 and ST380 are the same as those at stepsST370 and ST380 of FIG. 6B. Note that although here a route search isperformed at step ST439, without performing another route search, asearch route to the last destination (e.g., “Yokohama Station”), i.e.,the route searched for at step ST120 of FIG. 6A, may be used as it is.

On the other hand, at step ST435, the destination setting unit 1 obtainsthe last destination's neighboring area (first destination's neighboringarea) from a destination's neighboring area setting unit 5, and sets adestination (second destination) within a range of the obtained firstdestination's neighboring area. Note that specific operation at thisstep ST435 is the same as that at step ST350 of FIG. 6B. For example,when the linguistic expression input last time is “Yokohama Station” andthe linguistic expression input this time is “Japan A Hotel”, thedestination setting unit 1 sets a destination for Japan A Hotel within afirst destination's neighboring area for “Yokohama Station”. Thereafter,route guidance is provided with the second destination being adestination.

The destination's neighboring area setting unit 5 sets a range of adestination's neighboring area (hereinafter referred to as a seconddestination's neighboring area), based on the distance between thecurrent location and the second destination (step ST360), the routesearch unit 3 searches for a route from the current location to thesecond destination (step ST370), and the route guidance unit 4 providesroute guidance to the second destination (step ST380). Specificoperations at steps ST360 to ST380 are the same as those at steps ST360to ST380 of FIG. 6B as described in the second embodiment.

Thereafter, processing returns to step ST400 and subsequent processesare repeated. That is, an inquiry question is output again and processesare repeated until a destination where the user wants to go is obtained(until a final destination is set).

As described above, according to the third embodiment, even by a vagueinstruction which is close to a human sense as if the user asks a taxidriver his/her destination, the vehicle can start to run by drawing asearch route to a destination's direction, and a spot that the userwants to go to finally can be set as a pinpoint destination, and thus,the user can arrive at the final destination.

Fourth Embodiment

In the first to third embodiments, it is assumed that the linguisticexpression input by a user can be one keyword (e.g., “Yokohama”). In theFourth embodiment, an embodiment will be described in which even when alinguistic expression including two or more keywords (e.g., “YokohamaChinatown”) is received, a destination and a destination's neighboringarea can be set.

FIG. 17 is a configuration diagram of a route-guidance control deviceaccording to the fourth embodiment of the invention.

Note that overlapping descriptions of the same configurations as thosedescribed in FIG. 5 in the second embodiment will be omitted.

The difference between the fourth embodiment and the second embodimentis, as shown in FIG. 17, that the device further includes anumber-of-keyword determination unit 12 and a keyword divider 13.

The number-of-keyword determination unit 12 determines whether areceived linguistic expression includes one keyword (a word) or two ormore keywords (words).

The keyword divider 13 divides the received linguistic expression intotwo or more keywords.

FIG. 18 is a flowchart for describing the operation of theroute-guidance control device according to the fourth embodiment of theinvention. With reference to FIG. 18, the operation will be described.In this regard, it is assumed that, for example, a linguistic expressionincluding two keywords “Yokohama Chinatown” is received and a pluralityof search criteria for setting a destination are those shown in FIG. 3.

A destination setting unit 1 receives data about where a user wants togo, which is input from an input device (step ST100). Step ST100 is thesame as step ST100 of FIG. 6A as described in the second embodiment.

The number-of-keyword determination unit 12 determines whether thenumber of keywords included in the linguistic expression received atstep ST100 is equal to one (step ST710). Counting of the number ofkeywords may be performed using existing techniques.

If it is determined at step ST710 that the number of keywords includedin the received linguistic expression is equal to one (if “YES” at stepST710), the number-of-keyword determination unit 12 transmits thereceived linguistic expression to the destination setting unit 1, andthe destination setting unit 1 performs processes at and after stepST110 of FIG. 6A. Specific operations are the same as those described inthe second embodiment and thus the detailed descriptions will beomitted.

If it is determined at step ST710 that the number of keywords includedin the received linguistic expression is not equal to one (if “NO” atstep ST710), the keyword divider 13 divides the received linguisticexpression into keywords (step ST720). Here, since it is assumed thatthe linguistic expression “Yokohama Chinatown” is received, the keyworddivider 13 divides the linguistic expression into two keywords, thefirst keyword “Yokohama” and the second keyword “Chinatown”. The keyworddivision may also be performed using existing techniques.

The destination setting unit 1 sets a candidate for a destination(referred to as first candidate for a destination) using the firstkeyword obtained by the division at step ST720 (step ST730).Specifically, the destination setting unit 1 sets “Yokohama Station” tothe first candidate for a destination, based on the word “Yokohama”which is the first keyword.

A destination's neighboring area setting unit 5 sets a range of acandidate for a destination's neighboring area (referred to as firstcandidate for a destination's neighboring area), based on a distancebetween the current location and the first candidate for a destination(step ST740).

The destination setting unit 1 sets a candidate for a destination(second candidate for a destination) in the range of the first candidatefor a destination's neighboring area which is set by the destination'sneighboring area setting unit 5 at step ST740, based on the secondkeyword (step ST750). Specifically, the second keyword “Chinatown” isset as the second candidate for a destination. In this regard, if thecandidate for a destination set at this step ST750 is the one set basedon the last keyword, then the destination setting unit 1 sets this as adestination. That is, here, since “Chinatown” is the candidate for adestination that is set using the last keyword, “Chinatown” becomes adestination.

When there are a plurality of second candidates for a destination whichare set using the second keyword within the first candidate for adestination's neighboring area, for example, the spot that is closest indistance from the first candidate for a destination may be set as thesecond candidate for a destination.

The destination's neighboring area setting unit 5 sets a destination'sneighboring area candidate (referred to as second candidate for adestination's neighboring area) in accordance with a distance betweenthe first candidate for a destination determined by the destinationsetting unit 1 at step ST730 and the second candidate for a destinationwhich are set by the destination setting unit 1 at step ST750 (stepST760). For a specific determination method for the second candidate fora destination's neighboring area, as with those described using FIGS. 7and 8 in the second embodiment, the destination's neighboring areasetting unit 5 has stored predetermined conditions for a range of adestination's neighboring area in accordance with the distance betweenthe first candidate for a destination and the second candidate for adestination, and sets the second candidate for a destination'sneighboring area in accordance with the conditions. The distance betweenthe first candidate for a destination and the second candidate for adestination and the range of a candidate for a destination's neighboringarea based on the distance can be set as appropriate. Note also that aswith the destination, the destination's neighboring area setting unit 5sets a candidate for a destination's neighboring area set using the lastkeyword, as a destination's neighboring area. Therefore, the secondcandidate for a destination's neighboring area is set as a destination'sneighboring area.

A route search unit 3 searches for a route from a current location tothe destination (step ST770), and a route guidance unit 4 guides theroute searched for at step ST770 (step ST780).

Here, the processes at steps ST730 to ST780 will be described referringto FIGS. 19A and 19B.

As shown in FIG. 19A, at step ST730, “Yokohama Station” is set as afirst candidate for a destination by the first keyword “Yokohama”, andat step ST740 a first candidate for destination's neighboring area for“Yokohama Station” (first candidate for a destination) is set. Then, atstep ST750, a second candidate for a destination for the second keyword“Chinatown” is set within a range of the first candidate for adestination's neighboring area. Furthermore, at step ST760, a secondcandidate for destination's neighboring area in accordance with thedistance between “Yokohama Station” (first candidate for a destination)and “Chinatown” (second candidate for a destination) is set. In thisregard, since the Chinatown (second candidate for a destination) is acandidate for the destination that is set using the last keyword amongthe keywords included in the received linguistic expression, thedestination setting unit 1 sets the Chinatown (second candidate for adestination) as a destination, and sets the second candidate for adestination's neighboring area as a destination's neighboring area.

When a route from a current location to the destination is searched forat step ST770, at step ST780, as shown in FIG. 19B, route guidancestarts.

Note that although here, as shown in FIG. 19B, the destination and thedestination's neighboring area are displayed on a screen upon routeguidance, the configuration is not limited thereto, and the destinationand the destination's neighboring area may not be displayed on a screen,or candidates for destination's neighboring area may also be displayedon a screen.

As such, in the fourth embodiment, the number-of-keyword determinationunit 12 decides the number of keywords (words) included in a receivedlinguistic expression. When the received linguistic expression includesa plurality of keywords (words), the keyword divider 13 divides thereceived linguistic expression into keywords. A candidate for adestination and a candidate for a destination's neighboring area foreach of the keywords obtained by the division are set in order from thefirst keyword. The settings of a candidate for a destination and acandidate for a destination's neighboring area for a next keyword withinthe candidate for a destination's neighboring area that are setimmediately before the next keyword are repeated. When a candidate for adestination and a candidate for a destination's neighboring area for thelast keyword are set, the candidate for a destination for the lastkeyword is set as a destination.

By this, a narrower area can be set as a destination's neighboring area,compared to the case of inputting only “Yokohama” from a currentlocation or inputting only “Chinatown”. In addition, if only “Chinatown”is input, then there is a possibility that a plurality of “Chinatowns”may appear as candidates from all around the country. Hence, YokohamaChinatown which is the location that the user wants to go to needs to besearched for, selected, and determined from the plurality of searchresults. On the other hand, when “Yokohama Chinatown” is input, onlyYokohama Chinatown can be securely set as a destination.

Note that although here the case of two keywords such as “YokohamaChinatown” is described as an example, in the case of three or morekeywords, a candidate for a destination and a destination's neighboringarea may be set in turn for each keyword, and a candidate for adestination that is set from the last keyword may be set as adestination. For example, in the case of “Yokohama Chinatown Japan AHotel”, a candidate for a destination for “Chinatown” that exists in acandidate for a destination's neighboring area for “Yokohama” may beset, and a destination for “Japan A Hotel” that exists in a candidatefor a destination's neighboring area for “Chinatown” may be further set.

In addition, although here, of “Yokohama Chinatown”, “Yokohama” thatappears first is considered the first keyword and “Chinatown” thatappears next is considered the second keyword, the configuration is notlimited thereto, and the order of keywords may be set according to thelanguage. For example, in the case of Japanese, the order of keywords is“Yokohama Chinatown” and it is assumed that an area that appears first(“Yokohama”) is wider than an area that appears next (“Chinatown”). Onthe other hand, in the case of English, like “Times Square in New York”,an area that appears later (“New York”) is larger than an area thatappears first (“Times Square”). In such a case, a setting may beperformed such that “New York” is the first keyword.

As described above, according to the fourth embodiment, even when alinguistic expression including a plurality of keywords is input, adestination and a destination's neighboring area can be set. Inaddition, a destination and a destination's neighboring area can befurther narrowed compared to the case of inputting a linguisticexpression by one keyword, and thus, when the destination's neighboringarea is displayed on a screen, the displayed area can be furtherapproximated to the one expected by the user.

Fifth Embodiment

In the first embodiment, when there is a station, facility or otherentity which has the same name as a linguistic expression input by auser, location information indicating the station, facility or otherentity which has the same name as the input linguistic expression isobtained from the map DB 2 to thereby set a destination. However, whenlocation information cannot be obtained from the map DB 2 because alinguistic expression is input for which there is no station, facilityor other entity which has the same name as the input linguisticexpression, a destination cannot be set. In the fifth embodiment, anembodiment will be described in which even if a linguistic expression isinput for which location information cannot be obtained from the map DB2, a destination can be set.

FIG. 20 is a configuration diagram of a route-guidance control deviceaccording to the fifth embodiment of the invention.

The difference between the fifth embodiment and the first embodiment is,as shown in FIG. 20, that a destination setting unit 1 refers to a maprendering database (hereinafter referred to as a map rendering DB) 14.

The map rendering DB 14 has stored, for example, the region names(characters used for map rendering), display ranges, display content,and maximum and minimum scales of geographic information.

FIG. 21 is a flowchart showing the operation of the route-guidancedevice according to the fifth embodiment of the invention. Note thatsteps ST100, ST120, and ST130 of FIG. 21 are the same as steps ST100,ST120, and ST130 of FIG. 2 described in the first embodiment, and thus,a detailed description is omitted. Here, the following description ismade assuming that the linguistic expression “Miura Peninsula” that isnot included in names of municipalities or station names is input and adestination search is performed using the plurality of search criteriashown in FIG. 3.

When data about a linguistic expression (“Miura Peninsula”) indicatingwhere a user wants to go is received at step ST100, the destinationsetting unit 1 searches for a destination based on the plurality ofsearch criteria of FIG. 3. At this time, there is no “station” or “nameof prefecture or municipality” having the same name as “MiuraPeninsula”, but the characters displayed on a map include the samecharacters (“Miura Peninsula”) as the input linguistic expression.Hence, the destination setting unit 1 accesses to the map rendering DB14 and sets the coordinates of a location of the characters displayed onthe map, as a destination (step ST810). Specifically, the destinationsetting unit 1 transforms the center of a display range of thecharacters (“Miura Peninsula”) which are displayed on the map and storedas characters to be used for map rendering, into location coordinates onthe map, and further sets the transformed location coordinates as adestination. Note that a method for transforming into locationcoordinates on the map may be based on latitude and longitude, but themethod is not limited thereto, and any method may be employed as long asthe location coordinates of the center of a display range of charactersdisplayed on the map can be obtained.

The process at step ST810 will be described referring to FIGS. 22A and22B.

The destination setting unit 1 transforms the center of a display rangeon a map where “Miura Peninsula” is displayed, such as that shown inFIG. 22A, into location coordinates and sets the location coordinates asa destination.

In addition, it is assumed that, for example, data about the word“Iwase” located in Iwase, Kamakura City is received at step ST100. Inthis case, “Iwase” is, as with “Miura Peninsula”, not included in namesof municipalities or station names nor in government offices orintersection names, but is written on the map (see FIG. 22B), and thename of the geographic information “Iwase” together with its displayrange is stored in the map rendering DB 14.

The destination setting unit 1 transforms the center of the displayrange on the map where “Iwase” is displayed, such as that shown in FIG.22B, into location coordinates and sets the location coordinates as adestination.

The description returns to the flow of FIG. 21.

A route search unit 3 searches for a route from a current location tothe destination set by the destination setting unit 1 at step ST810(step ST120), and a route guidance unit 4 provides route guidance (stepST130). Specific operations at steps ST120 and ST130 are the same asthose at steps ST120 and ST130 of FIG. 2 as described in the firstembodiment.

As described above, according to the fifth embodiment, even if alinguistic expression is input for which location information indicatinga station, facility or other entity which has the same name as the inputlinguistic expression cannot be obtained from the map DB, a destinationcan be set.

Sixth Embodiment

In the fifth embodiment, the embodiment has been described in which, inthe case where a linguistic expression is input for which locationinformation indicating a station, facility or other entity which has thesame name as the input linguistic expression cannot be obtained from themap DB 2, if there are characters such as a name displayed on a map,then a destination can be set based on the location represented by thecharacters. In the sixth embodiment, an embodiment will be described inwhich a destination is set even when a name is input for which locationinformation indicating a station, facility or other entity which has thesame name as the input linguistic expression cannot be obtained from themap DB 2, or when names (e.g., an area called its commonly known name)which are not displayed on a map are input.

A configuration of a route-guidance control device according to thesixth embodiment is the same as that described in FIG. 1 in the firstembodiment and thus is omitted.

FIG. 23 is a flowchart for describing the operation of theroute-guidance control device according to the sixth embodiment of theinvention. Note that steps ST100, ST120, and ST130 of FIG. 23 are thesame as steps ST100, ST120, and ST130 of FIGS. 2 and 21 described in thefirst and fifth embodiments and thus a detailed description is omitted.Here, the following description is made assuming that the linguisticexpression “Shonan” is input and a destination search is performed usingthe plurality of search criteria shown in FIG. 3.

When data about a linguistic expression (“Shonan”) indicating where auser wants to go is received at step ST100, a destination setting unit 1searches for a destination based on the plurality of search criteria. Atthis time, there is no “station” or “name of prefecture or municipality”having the same name as “Shonan”, but there are a plurality of names offacilities including the name “Shonan”. The destination setting unit 1accesses a map DB 2 to search for the name of the facility that includesa received character string (step ST910).

The destination setting unit 1 sets a destination based on adistribution of facilities that are obtained as a result of the searchat step ST910 (step ST920). Specifically, the destination setting unit 1divides a map by meshes, checks a distribution of facilities in eachmesh, identifies a mesh having the largest number of correspondingfacilities, and sets the coordinates of a location of the center of themesh as a destination (see FIG. 24). Note that the setting of adestination is not limited thereto, and taking into account thedistribution density of facilities, the center of the distributiondensity may be set as a destination. As such, the destination can be setas appropriate.

A route search unit 3 searches for a route from a current location tothe destination set by the destination setting unit 1 at step ST920(step ST120), and a route guidance unit 4 provides route guidance (stepST130). Specific operations at steps ST120 and ST130 are the same asthose at steps ST120 and ST130 of FIG. 2 described in the firstembodiment.

As described above, according to the sixth embodiment, a destination canbe set even when location information indicating a station, facility orother entity which has the same name as an input linguistic expressioncannot be obtained from the map DB and also when the same name as theinput linguistic expression is not displayed on a map.

Seventh Embodiment

In the first embodiment, a destination is set in accordance with theorders of priority of a plurality of search criteria. In the seventhembodiment, an embodiment will be described in which when, in additionto a high-preferential candidate for a destination, there are furthercandidates for a destination that apply to search criteria and that arecloser in distance from a current location than the high-preferentialcandidate for a destination is, a destination is set taking into accounta distance from the current location.

A configuration of a route-guidance control device according to theseventh embodiment is the same as that described in FIG. 1 in the firstembodiment and thus is omitted.

FIG. 25 is a flowchart for describing the operation of theroute-guidance control device according to the seventh embodiment of theinvention. Note that steps ST100, ST120, and ST130 of FIG. 25 are thesame as steps ST100, ST120, and ST130 of FIG. 2 described in the firstembodiment and thus a detailed description is omitted.

When data about a linguistic expression indicating where a user wants togo is received at step ST100, a destination setting unit 1 searches fordestinations that can be searched for using a plurality of searchcriteria, in accordance with the orders of priority and decides whetherthere are a plurality of destinations that apply to the search criteria,i.e., whether there are destinations that can be searched for using aplurality of search criteria in addition to a destination that can besearched for using a highest-priority search criterion (referred to aspreferential destination) (step ST1010).

If there are no plurality of destinations that apply to search criteriaat step ST1010, i.e., if there is only one destination (if “NO” at stepST1010), the destination setting unit 1 sets the preferentialdestination, i.e., a single destination because only the singledestination applies to a search criterion, as a destination (stepST1040).

On the other hand, if there are destinations that apply to a pluralitysearch criteria in addition to the preferential destination at stepST1010 (if “YES” at step ST1010), the destination setting unit 1accesses to the map DB 2 and calculates a distance between the currentlocation and each of the destinations that apply to the search criteria,and further decides whether there are destinations whose distances fromthe current location are shorter than a distance between the currentlocation and the preferential destination (referred to as short-distancedestinations) (step ST1020).

If there are no short-distance destinations at step ST1020 (if “NO” atstep ST1020), the destination setting unit 1 sets the preferentialdestination to be a destination (step ST1040).

If there are short-distance destinations at step ST1020 (if “YES” atstep ST1020), the destination setting unit 1 decides whether theshort-distance destinations satisfy a setting condition in advance (stepST1030). Here, for example, the setting condition is that “comparing tothe distance between the current location and the preferentialdestination, the distance from the current location to theshort-distance destination is less than or equal to 1/10 of the distancefrom the current location to the preferential destination”.

If there is a short-distance destination that satisfies the settingcondition at step ST1030 (if “YES” at step ST1030), the destinationsetting unit 1 sets the short-distance destination that satisfies thesetting condition, as a destination (step ST1050). That is, here, ashort-distance destination whose distance from the current location isless than or equal to 1/10 of the distance to the preferentialdestination is set as a destination. Note that when there are aplurality of corresponding short-distance destinations, a short-distancedestination closer to the current location may be set as a destination.

If there is no spot that satisfies the setting condition at step ST1030(if “NO” at step ST1030), the destination setting unit 1 sets thepreferential destination as a destination (step ST1040).

A route search unit 3 searches for a route to the destination set by thedestination setting unit 1 (step ST120), and route guidance is provided(step ST130). Specific operations at steps ST120 and ST130 are the sameas those at steps ST120 and ST130 of FIG. 2 as described in the firstembodiment.

Note that the setting condition may be that “the distance between thecurrent location and the short-distance destination is shorter than thedistance from the current location to the preferential destination”. Assuch, the setting condition can be set as appropriate.

As described above, according to the seventh embodiment, for example,even when a plurality of different spots such as a station name and anintersection name are considered destinations, a destination that ismore suitable for a user's situation can be set.

Eighth Embodiment

Although the above first to seventh embodiments describe that theroute-guidance control devices of the invention may be applied toautomotive navigation systems, the application is not limited tonavigation devices in automotive navigation systems and may benavigation devices for movable bodies including humans, vehicles,railroads, boats, aircraft or other entities, or may be servers innavigation systems. In addition, the route-guidance control devices ofthe invention can also be applied to things in any form, such asnavigation system applications which are installed on portableinformation terminals such as smartphones, tablet PCs, and mobilephones.

FIG. 26 is a diagram showing an overview of a navigation system of aneighth embodiment of the invention. The navigation system can adoptvarious modes, e.g., an in-vehicle device 100 performs a route-guidancecontrol process in cooperation with at least one of a portableinformation terminal 101, such as a smartphone, and a server 102, or atleast one of the portable information terminal 101, such as asmartphone, and the server 102 performs route-guidance control and mapinformation is displayed on the in-vehicle device 100. A configurationmode of the navigation system will be described below.

Description will be made of a case in which in the navigation system ofthe eighth embodiment, the server 102 performs a route-guidance controlprocess, and results of the route-guidance control are displayed on thein-vehicle device 100 and thereby provided to a user, and a case inwhich the portable information terminal 101 performs a route-guidancecontrol process in cooperation with the server 102, and results of theroute-guidance control are displayed on the in-vehicle device 100 andthereby provided to the user, in addition to a case in which thein-vehicle device 100 shown in FIG. 26 have all functions of theroute-guidance control devices of the first to seventh embodiments.

First, the case in which the server 102 performs route-guidance controland results of the route-guidance control are displayed on thein-vehicle device 100, i.e., a case in which the in-vehicle device 100functions as a display device in cooperation with the server 102 havinga route-guidance control function, will be described.

In this configuration, a case is considered in which the in-vehicledevice 100 directly communicates with the server 102 or the in-vehicledevice 100 communicates with the server 102 via the portable informationterminal 101.

The server 102 functions as a guidance control device including adestination setting unit 1, a map DB 2, a route search unit 3, adestination's neighboring area setting unit 5, a current-locationacquiring unit 6, an inquiry timing decider 7, an inquiry sentencegenerator 8, a keyword discriminator 10, a destination determinationunit 11, a number-of-keyword determination unit 12, a keyword divider13, and a map rendering DB 14 which are described in the first toseventh embodiments. In addition, the in-vehicle device 100 functions asa display device including at least a display unit for providing a userwith results of route-guidance control performed by the server 102.

In this case, the in-vehicle device 100 basically has only acommunication function and a display function, and receives results ofroute-guidance control performed by the server 102 and provides the userwith the results.

Specifically, the server 102 is a route-guidance control deviceincluding the destination setting unit 1, the map DB 2, the route searchunit 3, the destination's neighboring area setting unit 5, thecurrent-location acquiring unit 6, the inquiry timing decider 7, theinquiry sentence generator 8, the keyword discriminator 10, thedestination determination unit 11, the number-of-keyword determinationunit 12, the keyword divider 13, and the map rendering DB 14, and theserver 102 which is the route-guidance control device allows thein-vehicle device 100 which is the display device to display generatedresults of route-guidance control.

Even by such a configuration, the same effects as those obtained in thefirst to seventh embodiments can be obtained.

Note that in addition to the above, the configuration may be such thatthe server 102 includes only the map DB 2 and the map rendering DB 14,and the in-vehicle device 100 including a route-guidance control deviceperforms a route-guidance control process by communicating with the mapDB in the server 102, and displays results of the route-guidancecontrol.

In addition, the case in which the portable information terminal 101performs a route-guidance control process in cooperation with the server102, and the in-vehicle device 100 provides the user with results of theroute-guidance control will be described.

In this configuration, a case in which the in-vehicle device 100communicates with the server 102 via the portable information terminal101 is considered, and an application of the portable informationterminal 101 performs a route-guidance control process in cooperationwith the server 102. In addition, the in-vehicle device 100 functions asa display device including at least a display unit for providing theuser with results of the route-guidance control performed by theportable information terminal 101 and the server 102.

In this case, too, the in-vehicle device 100 basically has only acommunication function and a display function, and receives results ofroute-guidance control performed by the portable information terminal101 and the server 102 in cooperation with each other, and provides theuser with the results.

Specifically, by the application of the portable information terminal101, results of route-guidance control are displayed on the in-vehicledevice 100 which is the display device.

Even by such a configuration, the same effects as those obtained in thefirst and second embodiments can be obtained.

Note that in this case, too, the configuration may be such that theserver 102 includes only the map DB 2 and the map rendering DB 14, andthe in-vehicle device 100 including a route-guidance control deviceperforms a route-guidance control process by communicating with the mapDB in the server 102 by the application of the portable informationterminal 101, and displays results of the route-guidance control.

It is to be understood that, within the scope of the invention, anarbitrary combination of two or more of the above-mentioned embodimentscan be made, various changes can be made in an arbitrary component ofany one of the above-mentioned embodiments, and an arbitrary componentof any one of the above-mentioned embodiments can be omitted.

INDUSTRIAL APPLICABILITY

A route-guidance control device according to the invention can perform aroute search by a vague instruction which includes nearly human feelingsas if a user tells a taxi driver as to where the user wants to go, evenwithout knowing the location on a map where the user wants to go, oreven without the building of area data in advance, and can allow avehicle to start to run immediately toward the area where the user wantsto go. Thus, the route-guidance control device can be applied to aroute-guidance control device that sets a destination area by a vagueinstruction for the route-guidance that is performed by an automotivenavigation system or the like, and then provides route-guidance to afinal destination as necessary.

REFERENCE SIGNS LIST

1: Destination setting unit, 2: Map DB, 3: Route search unit, 4: Routeguidance unit, 5: Destination's neighboring area setting unit, 6:Current-location acquiring unit, 7: Inquiry timing decider, 8: Inquirysentence generator, 9: Input unit, 10: Keyword discriminator, 11:Destination determination unit, 12: Number-of-keyword determinationunit, 13: Keyword divider, 14: Map rendering DB, 100: In-vehicle device,101: Portable information terminal, and 102: Server.

The invention claimed is:
 1. A route-guidance control device comprising:a processor; and a memory coupled to the processor, the memory storinginstructions which, when executed by the processor, causes the processorto perform a process including accessing to a map database storing mapinformation to search for a destination corresponding to an inputlinguistic expression, using a plurality of search criteria providedwith orders of priority; setting a first destination corresponding tothe input linguistic expression, in accordance with the orders ofpriority; and setting a range of a neighboring area surrounding thefirst destination in such manner that the range increases as a distancebetween a current location and the first destination increases, whereinthe process further includes allowing output of an inquiry sentence whenthe current location and a location of the first destination'sneighboring area satisfy a setting condition; and receiving data about alinguistic expression for responding to the inquiry sentence to set asecond destination in the first destination's neighboring area, whereinthe process further includes deciding whether a linguistic expressioninput last time is the same as a linguistic expression input this time;and setting a currently set destination to a final destination when thelinguistic expression input last time is the same as the linguisticexpression input this time.
 2. The route-guidance control deviceaccording to claim 1, wherein the process further sets a range of thefirst destination's neighboring area, in accordance with the pluralityof search criteria used to set the first destination.
 3. Theroute-guidance control device according to claim 1, wherein the processcauses the first destination's neighboring area to be displayed on adisplay device.
 4. The route-guidance control device according to claim1, wherein the process further includes: determining a number of wordsincluded in the input linguistic expression; and when the inputlinguistic expression is determined to include a plurality of words,dividing the input linguistic expression into the plurality of words,wherein the first destination is set based on the plurality of wordsobtained by the division.
 5. The route-guidance control device accordingto claim 1, wherein: a search criterion of map rendering information isincluded as one criterion of the plurality of search criteria, thesearch criterion being used for searching for a destination based oncharacter information to be used for map rendering; and locationcoordinates of the first destination set based on the search criterionof map rendering information are location coordinates of a center ofcharacters displayed on a map.
 6. The route-guidance control deviceaccording to claim 1, wherein: a facility search criterion is includedas one criterion of the plurality of search criteria, the facilitysearch criterion being used for searching for a destination based oninformation on one or more facilities having the input linguisticexpression; and location coordinates of the first destination set basedon the facility search criterion are set based on a distribution on amap of the one or more facilities.
 7. A route-guidance control devicecomprising: a processor; and a memory coupled to the processor, thememory storing instructions which, when executed by the processor,causes the processor to perform a process including accessing to a mapdatabase storing map information to search for a destinationcorresponding to an input linguistic expression, using a plurality ofsearch criteria provided with orders of priority; setting a firstdestination corresponding to the input linguistic expression, inaccordance with the orders of priority; and setting a range of aneighboring area surrounding the first destination in such manner thatthe range increases as a distance between a current location and thefirst destination increases, wherein the process further includesallowing output of an inquiry sentence based on an input from anexternal source; and receiving data about a linguistic expression forresponding to the inquiry sentence to set a second destination in thefirst destination's neighboring area, wherein the process furtherincludes deciding whether a linguistic expression input last time is thesame as a linguistic expression input this time; and setting a currentlyset destination to a final destination when the linguistic expressioninput last time is the same as the linguistic expression input thistime.
 8. A route-guidance control device comprising: a processor; and amemory coupled to the processor, the memory storing instructions which,when executed by the processor, causes the processor to perform aprocess including accessing to a map database storing map information tosearch for a destination corresponding to an input linguisticexpression, using a plurality of search criteria provided with orders ofpriority; setting a first destination corresponding to the inputlinguistic expression, in accordance with the orders of priority; andsetting a range of a neighboring area surrounding the first destinationin such manner that the range increases as a distance between a currentlocation and the first destination increases, wherein: the processsearches for destinations that are searchable by the plurality of searchcriteria, in accordance with the orders of priority; and if apreferential destination exists as a destination being searchable by asearch criteria having a high-order of the priority and, in addition, ashort-distance destination exists as a destination being searchable bythe plurality of search criteria and having a distance from the currentlocation shorter than a distance between the current location and thepreferential destination, the process sets the first destination to theshort-distance destination when the short-distance destination satisfiesa setting condition.